For the price of a USB ALDL cable (around $40-60), you can have dealer-level diagnostics from the early 1990s. Terry may not have a corporation or a tech support line, but his Mode 22 scan tool has kept more vintage GMs on the road than any dealership recall. Download it, connect it, and finally see what your old GM is really thinking.

Turn the ignition to ON (engine off for sensor checks) or start the engine. Click “Connect” or “Scan Mode 22”.

The GM Mode 22 scan tool has various applications in the automotive industry, including:

: Terry's tool became a staple on forums like Scantool.net and early car-tuning communities. It paved the way for modern, affordable bi-directional scanners from brands like Launch and Autel that we use today.

Based on the existing reputation of "Terry" (likely Terry Johnson of ) and his existing software (Terry's GM Scan Tool), the most logical and high-impact feature to add would be a "Bi-Directional Smart-Actuator Dashboard."

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